Flexible coupling

ABSTRACT

A coupling 1, 50, 100 for joining adjacent frame members 2, 3 of a fish breeding enclosure 5 comprises a first mounting means 10, 52, 105, 106 for mounting to one frame member 2, a second mounting means 11, 53, 105, 106 for mounting to another frame member 3 and a flexible body 12, 51, 101 of elastomeric material between the first and second mounting means 10, 11, 52, 53, 105, 106. The coupling 1, 50, 100 constrains relative rotational and translational movement between the frame members 2, 3 in use to a predetermined level which is determined by the material of the flexible body 12, 51, 101 and/or by mechanical limit stops 62, 63. A non flexible connection such as a rod 35 having flanges 36, 37 or a chain 90, 110 provides a mechanical connection between the mounting means 10, 11, 52, 53, 105, 106 in the event of failure of the flexible body 12, 51, 101.

FIELD OF THE INVENTION

The invention relates to a coupling for joining frame members of a fishbreeding enclosure framework.

Fish breeding enclosures comprising a framework formed byinterconnecting frame members are known. In one known arrangement theframe members are pivotally interconnected by a pivot pin arrangementfor pivotal movement about a pivot axis transverse to the longitudinalaxis of the frame member to which it is attached. However, the forceswhich such enclosures can accommodate are relatively small so that suchenclosures have limited application both in terms of their size and inthe waterways in which they may be sited.

SUMMARY OF THE INVENTION

According to the invention there is provided a coupling for joiningframe members of a fish breeding enclosure framework, the couplingcomprising:

a first mounting means for mounting to a frame member,

a second mounting means for mounting to another frame member, and

a connecting body of flexible material between the first and secondmounting means, the body deforming in use in a controlled manner topermit relative rotational and translational movement between the framemembers in a predetermined manner.

In one embodiment of the invention the coupling includes connectionmeans between the mounting means or frame members to provide amechanical connection between the frame members in the event of failureof the flexible body. Advantageously the connection means comprises anon-flexible member extending between the mounting means.

In a particularly preferred embodiment of the invention bonding meansare provided for bonding the flexible body to the mounting means.

In one particularly important aspect of the invention the flexible bodyhas a longitudinal axis which extends generally transversely of thelongitudinal axis of the frame members.

In this case the flexible body is preferably confined within an outercasing forming the mounting means or to which the mounting means isattached.

Preferably the flexible body comprises at least two flexible body partsand connection means are provided between the body parts to constrainratational movement between the flexible body parts. Advantageously theflexible body parts have central co-axially arranged bores to receive acomplementary shaped rod.

Typically, each flexible body part is confined within an associatedouter casing part.

Preferably each flexible body is confined in a housing comprising aninner housing part and an outer housing part which are spaced-apart toconfine the flexible body therebetween, the inner housing part definingthe bore for reception of the rod and the outer housing part being aforce fit in the associated outer casing.

In this case preferably the inner housing part and the flexible bodyextends axially beyond at least one end of the outer housing part topermit relative translational movement between the flexible body partsin shear and compression along the axis of the flexible body parts, theends of the outer housing parts providing limit stops to limit themovement of the flexible body parts.

Preferably the inner bores defined by the inner housing parts arepolygonal in transverse cross section and the connecting rod is ofcomplementary polygonal shape for distributing loads applied to theframe members between the flexible body parts.

Typically the longitudinal axis of the flexible body part is inclinedwith respect to the longitudinal axis of the bore.

In this case preferably the longitudinal axes of adjacent flexible bodyparts are inclined with respect to each other.

In a particularly preferred embodiment of the invention the outer casingcomprises a central casing part associated with one frame member and apair of side casing parts flanking the central casing part and beingassociated with another frame member.

In one case the central casing part is approximately twice the width ofeach side casing part, there being four identical housing parts, onewithin each side casing part and two within the central casing part.

Preferably each outer housing part includes a radially outwardlyextending flange for locating and limiting the entry of the outerhousing into an associated casing.

In another particularly preferred aspect of the invention the outercasing comprises two longitudinally extending casing parts attached tothe flexible body and carrying the mounting means for mounting thecoupling to an associated frame member.

In this case the flexible body is preferably of generally curvilinearshape in transverse cross section.

In one case the flexible body is of generally hourglass shape intransverse cross section having a central narrow waist portion and apair of wider portions on either side of the waist portion.

Preferably the casing parts are shaped to conform with the shape of theflexible body.

In this case preferably each mounting means comprises a first platemember which extends in use longitudinally of the frame member to whichit is attached and a second plate member extending transversely of theframe member.

In another particularly preferred aspect of the invention the flexiblebody has a longitudinal axis which extends generally parallel to thelongitudinal axis of the frame members.

In this case preferably the mounting means comprises a plate member ateach end of the flexible body for attaching to adjacent frame members.

Preferably translation constraining means are provided to constraintranslational movement of the coupling along the longitudinal axis.

In a particularly preferred embodiment of the invention the translationconstraining means comprises:

first translational limiting means to limit movement of the flexiblebody in tension a predetermined amount; and

second translational limiting means to limit movement of the flexiblebody in compression a predetermined amount.

Typically, the first translation limiting means comprises a non-flexiblemember extending through the flexible body, the effective length of thenon-flexible member being set to permit only a predeterminedtranslational movement of the flexible body, additional tension forceapplied to the flexible body above a preset amount being taken up by thenon-flexible member.

Preferably the non-flexible member comprises an elongate rod having stopmeans to set the predetermined translational movement of the flexiblebody under tension.

Advantageously the stop means is adjustable to set the predeterminedtranslational movement of the flexible body under tension.

In one case the non-flexible member comprises a chain.

Preferably the second translational limiting means comprises a pair ofrigid stop members within the flexible body, the stop members beingspaced-apart to define therebetween a gap corresponding to apredetermined allowed translation movement of the flexible body incompression, additional compression force above a preset amount beingtaken up by the stop members.

Preferably the flexible body is an elongate body having a centralelongate core.

In one embodiment of the invention the flexible body in longitudinalcross section comprises a central enlarged portion and a pair of sidenarrower portions flanking the central portion.

The invention also provides a framework for a fish breeding enclosureincorporating a coupling according to the invention between the framemembers of the framework. Preferably there are at least two spaced-apartcouplings between adjacent frame members of the framework.

The invention also provides a fish breeding enclosure having a frameworkincorporating couplings according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription thereof given by way of example only with reference to theaccompanying drawings in which:

FIG. 1 is a plan, partially cross sectional view of a coupling accordingto one embodiment of the invention,

FIG. 2 is a perspective view of the coupling of FIG. 1, in use,

FIG. 3 is a side elevational view of part of the coupling,

FIG. 4 is a perspective view from one side of one part of the coupling,

FIG. 5 is a perspective view from the other side of the coupling part,

FIG. 6 is a cross sectional view of the coupling part of FIGS. 4 and 5,

FIG. 7 is a plan view of a typical layout of a fish breeding enclosureincorporating the couplings of the invention,

FIG. 8 is a plan view of a layout of another fish breeding enclosureincorporating couplings according to the invention,

FIG. 9 is a view on line IX--IX in FIG. 8,

FIG. 10 is a perspective partially cut-away view of a coupling accordingto another embodiment of the invention,

FIG. 11 is a longitudinal cross sectional view of the coupling of FIG.10,

FIG. 12 is a perspective view of another coupling according to theinvention,

FIG. 13 is another perspective view of the coupling of FIG. 12 from adifferent direction,

FIG. 14 is a cross sectional view of the coupling along the lineXIV--XIV in FIG. 13,

FIG. 15 is a diagrammatic perspective view illustrating the coupling ofFIGS. 12 and 14, in use, and

FIG. 16 is a diagrammatic plan view illustrating couplings of FIGS. 12to 14, in use.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings and initially to FIGS. 1 to 9 thereof there isillustrated a coupling according to one embodiment of the invention andindicated generally by the reference numeral 1. The coupling 1 is usedfor joining adjacent frame members 2, 3 of a fish breeding enclosure 5.It will be noted that in this case a central longitudinal axis L of thecoupling 1 is arranged substantially transversely of the adjacent framemembers 2, 3 to which it is attached. Some typical layouts of fishbreeding enclosures incorporating the couplings 1 according to theinvention are illustrated in FIGS. 7 to 9.

Referring in particular to FIGS. 1 to 6 the coupling 1 in general termscomprises a first mounting means 10 for mounting to one frame member 2and a second mounting means 11 for mounting to another adjacent framemember 3. A flexible body of elastomeric material is provided betweenthe first and second mounting means 10, 11 and the arrangement is suchthat the coupling 1 allows controlled relative rotational andtranslational movement between the frame members 2, 3 in use to apredetermined level. As will be described in more detail below the meansfor constraining the relative rotational and translational movementbetween the frame members 2, 3 is in some cases provided by theproperties of the elastomeric material of the flexible body and in othercases by mechanical stops.

The flexible body is divided into at least two flexible body parts, inthis case two pairs of flexible body parts, namely a central pair offlexible body parts 15, 16 associated with the first mounting means 10and an outer pair of flexible body parts 17, 18 flanking the centralpair of flexible body parts 15, 16 and being associated with the secondmounting means 11. The central body parts 15, 16 are confined within afirst outer casing part 20 which forms the first mounting means 10 or towhich the first mounting means 10 is rigidly secured. The outer flexiblebody parts 17, 18 are confined within second outer casing parts 21, 22respectively which form the second mounting means 11 or to which thesecond mounting means 11 is rigidly secured.

In this case and referring particularly to FIGS. 4 to 6 each flexiblebody part, for example, the flexible body part 15 is confined within ahousing which comprises an inner housing part 25 and an outer housingpart 26 which are radially spaced-apart to confine the annular flexiblebody part 15 therebetween. The outer housing part 26 is a force fit inthe associated outer casing part 20, 21 or 22 and includes a radiallyoutwardly extending flange 29 which, in use, locates and limits theentry of the outer housing part 26 into an associated casing part 20,21.

Each inner housing part 25 has a central longitudinally extending axialbore 30 which is preferably of polygonal shape, in this case, hexagonalshape, the bores 30 of each of the four inner housing parts 25 beingarranged co-axially as illustrated in FIG. 1 to form a centrallongitudinally extending hexagonal bore through the coupling 1.Connection means are provided between the flexible body parts toconstrain translational movement between the body parts in use and inthis case the connecting means comprises an elongate rod 35 ofcomplementary hexagonal shape to that of the bore, the rod havingradially outwardly extending washers or flanges 36, 37 which extend inuse to engage the vertical side edges of the second outer casing parts21, 22 as will be apparent from FIG. 1. The rod 35 may be screw threadedor in this case includes screw threaded extension portions 38, 39 onwhich the washers 36, 37 are mounted and fixed in position by lock nuts40. The effect of the rod 35 is to distribute load forces appliedbetween the flexible body parts 15, 16, 17, 18.

It will be noted that each inner housing part 25 extends axially beyondat least one end of the outer housing part 26 to permit relativetranslational movement between the flexible body parts in shear andcompression along the longitudinal axis, the ends of the outer housingparts 26 providing limit stops to limit the movement of the flexiblebody parts in compression. It will also be noted that the inner housingpart 25 is recessed with respect to the outer housing part 26 at thenon-flanged end thereof to accommodate translational movement of theflexible annular body part 15. It will also be noted from FIG. 6 thatthe annular body part 15 is of conical shape with an angle of taperL_(F) inclined with respect to the longitudinal axis L of the couplingand the angles of taper of adjacent flexible body parts are inclinedwith respect to each other (see FIG. 1) for accommodating loads appliedto the flexible body parts, in use.

For ease of manufacture, assembly and maintenance, there are, it will beappreciated, in the configuration just described, four identical partsillustrated in FIGS. 4, 5 and 6 which are assembled as illustrated inFIG. 1 and 3 into the central casing part 20 and the side casing parts21, 22 so that the flanges 29 are facing each other. The hexagonal rod35 is then inserted through the bores 30, the washers 36, 37 fitted andfixed in position by the lock nuts 40. The first and second mountingmeans 10, 11 are then attached to the frame members 2, 3 which arearranged to form a fish breeding enclosure 5 of any desired shape andconfiguration such as the configurations illustrated in FIGS. 7, 8 and9. Generally there will be two couplings provided at the joint betweenadjacent frame members. It will be appreciated that the shape andconfiguration of the mounting arrangement, for example, through a flangeand bolting arrangement or any suitable means is selected to achieve anydesired configuration of enclosure. The couplings facilitate mounting inmany different orientations as desired.

In use, the fish breeding enclosure incorporating the couplings 1 ismounted in a waterway and bending, tensile and shear forces developed inuse are accommodated by the coupling without excessive wear or damage tothe frame members and/or the couplings. Thus, the enclosures formedusing the couplings of the invention can take up the forces developed inrough weather when sections of the enclosure will be moved a significantdistance with respect to an adjacent section in response to waves andwater currents generally. The arrangement in this case is such thatrelative rotational and translational movement between the frame members2, 3 of the enclosure in use are constrained by the configuration, bymechanical stop means, and by the properties of the elastomeric materialforming the flexible coupling parts to predetermined levels. Compressionforces along the longitudinal axis L of the coupling is taken up by thestability of the flexible body parts 15, 16, 17, 18 until adjacentflanges 29 abut, the flanges 29 effectively forming limit stops to limitthe translational movement. Tension or extension forces along the axis Lare taken up by the flexible body parts and are limited by the flanges29 of the outer housing 26. The polygonal shape of the rod 35 and thebores in the inner housing parts 25 through which the rod 35 extends hasthe effect of distributing forces applied to the flange members throughthe first and second mounting means 10, 11 to each of the flexiblebodies.

The general advantages of the couplings according to the variousembodiments of the invention are outlined in detail below. Someparticular advantages of this embodiment are that because the flexiblebody is divided it has the effect of allowing a thinner section offlexible body to be used.

Preferably the material of the outer housing is non-metallic, mostpreferably of a non-metallic material which expands in sea water, suchas nylon. The flexible body may be relatively easily bonded to suchmaterial and the housing can be made to achieve a good interference fitwhich improves in use by expansion in the sea water.

The advantage of arranging the flexible body on an axis Lf which isinclined with respect to the longitudinal axis L is in providingimproved axial stiffness in use. Thus, for a given load a shorterdistance between the facing flanges 29 may be provided. A low frictionmaterial such as polytetrafluoroethylene (PTFE) may be bonded to thefaces of the flanges 29 to limit frictional engagement.

If a force is applied to the mounting part 10 which tends to rotate itabout the axis L, the force is spread between the parts and constrainedby the stiffness of the flexible body parts.

It will be appreciated that the rod 35 may have a limit stop weldedthereto and may be assembled using any suitable arrangement such as byinsertion through a washer which is fixed in place by a pin insertedthrough the rod.

Referring to FIGS. 10 and 11 there is illustrated another coupling 50according to the invention which in general terms is similar to thecoupling described above with reference to FIGS. 1 to 9 and is used in asimilar manner. In this case the longitudinal axis L1 of the coupling 50is in use arranged parallel to the longitudinal axis of the framemembers to which it is attached.

The coupling 50 comprises a flexible body 51 of a suitable flexibleelastomer material such as polyurethane, which is moulded around andbonded to a pair of end flanges 52, 53 which form a first and secondmounting means respectively for mounting to adjacent frame members ofthe fish breeding enclosure framework. The end flanges 52, 53 carrybolts 55 for mounting to elements of a fish breeding enclosure to formany suitable arrangement such as the arrangement illustrated in FIGS. 7to 9. In this case the flexible body 51 is of generally barrel-shapehaving a central wide portion 51A and a pair of side portions 51B, 51Cflanking the wide portion 51A.

Outer tubular elements 60, 61 are welded to and extend inwardly of theend flanges 52, 53 respectively. The inner ends of the tubular elements60, 61 are in turn welded to smaller diameter inner flanges 62, 63 whichare spaced-apart to define therebetween a central core which may behollow, or as in the case illustrated, may be filled with a lightweightand flexible foam material 66 such as a polyurethane foam which preventsthe elastomer filling the core.

Inner tubular elements 70, 71 of axially stepped configuration aredisposed within the outer tubular elements 60, 61. The inner tubularelements 70, 71 are not fixed to any other element of the coupling. Eachof the inner tubular elements 70, 71 includes a thick outer portion 70A,71A and a thinner inner portion 70B, 71B. The thinner inner portions70B, 71B are spaced-apart from the outer tubular elements 60, 61 todefine annular spaces 80, 81 respectively to accommodate a plurality ofspring members 85 which in this case are of hexagonal shape intransverse cross section. The spring members 85 which are preferably ofan elastomeric material may be of any desired shape such as of circularshape in transverse cross section. It will be noted that each of theoutermost and innermost spring members 85 are shaped with flat ends toform seals to prevent elastomer material passing into the space in whichthe spring members 85 are housed during moulding.

A chain 90 extends centrally through the inner tubular elements 60, 61and is attached to loadpins 91, 92 at either end which extend throughthe outermost links of the chain 90. The load pins 91, 92 are housed inslots 96 in a housing 97.

The outer flanges 52, 53, the bolts 55, the load pins 91, 92, the chain90 and all other spaces except for the space housing the spring members85 and the central core space is then encapsulated in a suitablepolyurethane based elastomer material.

The surfaces of the metal components of the coupling are preferablyroughened to assist in keying engagement and may alternatively oradditionally be c with an adhesive compound, if desired. Other chemicalbonding techniques may also be used.

In use, the couplings 50 are mounted to take up load forces applied bywaves and water currents generally in the water course in which the fishbreeding enclosure is mounted. The flexible coupling member 50 absorbstension, compression, shear and turning forces. The flexibility of theflexible body 51 and the hollow central core allows the flexible body 51to take up different configurations to accommodate the forces. To ensurethat the flexible body 51 does not break in use, the maximum force whichmay be applied may be limited, for example, by using the chain 90.Alternatively or additionally a steel cable or elongate rod may extendthrough the flexible body with stops at either end for a similarpurpose.

In use, the chain 90 provides a limit stop which limits the allowedtranslational motion of the flanges 52, 53 and hence the frame members2, 3. Once the extension of the flexible body 51 is beyond a presetlimit, the frame members 2, 3 are directly connected through the flanges52, 52 and the chain 90. Translational compression movement along thelongitudinal axis L1 of the coupling 50 is limited by the inner flanges62, 63 which engage when the flexible body is compressed beyond a presetlimit defined by the spacing between the flanges in the normal at restposition illustrated in FIG. 11. In tension, the spring members 85 arecompressed to fill the void 81 which then provides a direct connectionbetween the flanges 62, 63 through the chain 90. The spring members 85also have the effect of damping the load applied to the chain. The ratioof the volume of the void 81 to the seals 85 sets the level at whichload is taken up by the chain 90.

The particular advantages of this embodiment of the invention are thatbecause the flanges are simple plate members they may be readily mountedto frame members. The encapsulation of the various parts in the flexibleelastomeric material protects the various parts against corrosion.Because of the, flanges 62, 63, the spring members 85 and other aspectsof the coupling, the response of the coupling in use may be readilydesigned, for example by changing the width of the gap between theflanges 62, 63.

Referring to FIGS. 12 to 16 there is illustrated another couplingaccording to the invention indicated generally by the reference numeral100. The coupling 100 is similar to the coupling 1 described above withreference to FIGS. 1 to 9, the longitudinal axis L2 of the coupling inuse being arranged substantially transversely of the frame members 2, 3to which it is attached as illustrated in FIGS. 15 and 16. The coupling100 comprises a flexible body 101 of a suitable elastomeric materialwhich in this case is of generally curvilinear, in this case generallyhourglass shape, in transverse cross section having a central narrowwaist portion 101A and a pair of wider portions 101B on either side ofthe waist portion 101A. The flexible body 101 is confined by an outercasing comprising two longitudinally extending outer casing parts 102,103 attached to the flexible body 101 and carrying the mounting meansfor mounting the coupling 100 to the associated frame members 2, 3. Thecasing parts 102, 103 are shaped to conform with the shape of theflexible body as illustrated. Each mounting means for mounting thecoupling to frame members comprises a first plate member 105 whichextends in use longitudinally of the frame member to which it isattached and a second cranked plate member having a portion 106 whichextends transversely of the frame member. The plate members 105, 106,have bolt holes 107 for bolting the coupling 1 to the associated framemembers 2, 3 as will be apparent from FIGS. 15 and 16. A chain 110extends through the flexible body 101 and is attached to the casingparts 102, 103 to limit the degree of extension of the flexible body 101allowed along the longitudinal axis of the frame members and to providea fail-safe mechanism interconnecting the frame members in the event offailure of the flexible body 101. The degree of compression of theflexible body 101 along the axis of the frame members is limited by thefacing edges of the casing parts 102, 103 and the mounting platemembers. p The particular advantages of the coupling according to thisembodiment of the invention include its simplicity of construction andapplication. Because the flexible body is of generally curved,particularly hourglass shape there is a large surface area of mountingmeans to which the flexible body may be bonded. Further, by spreadingout the flexible body in this way there is more active flexible materialin strain so that the forces applied are distributed.

The advantages of all the embodiments of the invention are many. Byflexibly connecting frame members of a fish breeding enclosure togetherthe connections between the frame members can accommodate relativelylarge forces in a number of different directions. Thus, largerenclosures may be built and/or the enclosures may be sited in waterwayswhich have heretofore not been used because of the large forcesgenerated by water currents and waves in the waterway. The dynamicresponse of a fish breeding enclosure incorporating couplings accordingto the invention is substantially reduced. The couplings allow thegeometry of the enclosure to change in both rotation and translation toaccommodate water currents and waves passing through the enclosurewithout deformation in the frame members.

We have found that the flexible body should allow a rotational movementbetween the frame members of up to 30°, preferably up to 26°.

In each of the embodiments described above it will be apparent thatthere is no metal to metal contact which could cause wear in use. Thus,in addition to taking up forces applied by the water currents and wavesin the water course in which the fish breeding enclosure is mounted, thecouplings according to the invention will have a long life, in use.

It is anticipated that the couplings according to the invention willfacilitate the formation of much larger enclosures than has heretoforebeen possible.

Many variations on the specific embodiments of the invention describedwill be readily apparent and accordingly the invention is not limited tothe embodiments hereinbefore described which may be varied in bothconstruction and detail.

I claim:
 1. A fish breeding enclosure coupling for joining frame membersof a fish breeding enclosure framework to permit controlled movementbetween adjacent frame members in use, said coupling comprising;a firstmounting means for mounting to a frame member, said first mounting meanshaving a first outer casing part comprising a central casing partassociated with the one frame member; a second mounting means formounting to another frame member, said second mounting means having asecond outer casing part comprising a pair of side casing parts flakingsaid central casing part and being associated with the other framemember, said central casing part being approximately twice the width ofeach side casing part; a connecting body of flexible material betweensaid first and second mounting means, said connecting body comprising atleast two axially aligned flexible body parts; a housing for confiningeach flexible body part, each housing comprising an inner housing partand an outer housing part, each outer housing part being fitted into arespective one of the first and second outer casing parts of the firstand second mounting means and including a radially outwardly extendingflange for locating and limiting the entry of the outer housing partinto the associated outer casing part, said inner and outer housingparts of each housing being radially spaced-apart to confine therespective flexible body part therebetween, and each inner housing partdefining a bore aligned with the bores of the other inner housing partsto form a central longitudinally extending bore, there being fouridentical housings, one within each side casing part and two within thecentral casing part; a retaining rod extending axially through saidcentral longitudinally extending bore, said retaining rod being shapedto prevent relative rotational movement between said inner housing partsin use; and washer means on said retaining rod, said washer meansextending radially outwardly to engage said first and second outercasing parts in use.
 2. A coupling according to claim 1 wherein eachinner housing part and the associated flexible body part extend axiallybeyond at least one end of the respective outer housing part to permitrelative translational movement between adjacent flexible body part sinshear and compression along the axis of the flexible body parts, theends of the outer housing parts providing limit stops to limit themovement of the flexible body parts.
 3. A coupling according to claim 1wherein said inner bores defined by the inner housing parts arepolygonal in transverse cross section, and said retaining rod is ofcomplementary polygonal shape for distributing loads applied to theframe members between said flexible body parts.
 4. A coupling accordingto claim 1 wherein each flexible body part is disposed on an axisinclined with respect to the longitudinal axis of the longitudinallyextending bore.
 5. A coupling according to claim 4 wherein thelongitudinal axes of the material of adjacent flexible body parts areinclined with respect to each other.
 6. A coupling comprisinga firstmounting means for mounting on a first frame member; a second mountingmeans for mounting on a second frame member; a rod of polygonal crosssection passing through each of said first and second mounting means topivotally connect said first and second mounting means on a common pivotaxis; a plurality of coupling parts mounted on said rod in non-rotatablerelation, at least one coupling part being secured in said firstmounting means in non-rotatable relation and at least one coupling beingsecured in said second mounting means in non-rotatable relation, each ofsaid coupling parts including an outer annular housing part mounted in arespective mounting means, an inner housing part mounted on said rod,and an elastomeric annular body part of conical shape between said outerand inner housing parts to transfer loadings therebetween, said outerannular housing part having a radial flange on one side abutting saidrespective mounting means.
 7. A coupling according to claim 6 whereinthe inner housing part of each coupling part projects from within therespective outer housing part on one side thereof while being recessedwithin said outer housing part on an opposite side thereof.
 8. Acoupling according to claim 7 wherein the inner housing part of eachcoupling part contacts an inner housing part of an adjacent couplingpart.
 9. A coupling according to claim 8 wherein the elastomeric annularbody part of each coupling part is tapered, the taper of an elastomericannular body part of one coupling unit being in a direction opposite tothe taper of an elastomeric annular body part of an adjacent couplingunit.
 10. A coupling according to claim 6 wherein said first mountingmeans has a centrally disposed casing part mounting a pair of saidcoupling parts therein, and said second mounting means has a pair ofcasing parts receiving said casing part of said first mounting meanstherebetween, each casing part of said second mounting means having oneof said coupling parts therein.
 11. A coupling according to claim 10which further comprises a pair of washers on said rod, each washer beingdisposed at a respective end of said rod in abutment with said secondmounting means, and a pair of nuts, each nut being threaded on said rodagainst a respective washer.